Conduit for electric conductors



(No Model.) 2 Sheets-Sheet 2.

D. H. DORSETT.

GONDUIT POR E'LBGTRIG GONDUGTORS.

Patented Apr. Z0, 1886.

@and

lines.

UNITED STATES PATENT OFFICE..

DANIEL H. DORSET'I, (IF CHICAGO, ILLINOIS.

CNDUIT FOR ELECTRlC CONDUCTOR-S.

wncrr-rcATIoN ferming'paft of Letters Patent 10.340.432. dated A Pfil 20 1986- A pplieaton filed (h'loher 1.11395. Serial No. ITJJIG. (No model.) Patented in England October R0, i885, No. 13,109.

`To all whom it may concern:

Be it known that I, DANIEL II. DORsETT, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have 'invented certain new and useful Improvements in yConduits for Electric (lonductors, of which the following is a specification, reference being had to the drawings accompanying and forming a part of the same.

In underground systems it is often desirable to insulate and protectv 'one,`two, or a small number of conductors. Especially is this desirablcin cases where branch pipes or con-- duits are usedv connecting with larger main and described -such a system, and while my present invention relates more particularly'to the construction of the branch pipes in this system, yet the said pipes are generally useful and applicable to underground systems of many differentkinds.

The 'application referred to is of even date herewith, and numbered 176,691.

With a view more especially to providing economical and eiective underground protection in cases of this kind, I have constructed aconduit in the following manner: I placca metal pipe, preferably iron, around one or :more smaller tubes or rods o f brass, iron, or steel fixed at one-end to a stationary support. I then paclc in around the rods a plastic insulai ing material consisting of the residunm from partially-distilled coal-tar, crude petroleum, parafline, silicious sand, pulverized.

`ishes and cinders, xide of manganese, and

ammonium chloride, inthe proportions hereinafter stated. This compound is sufficiently soft when *hot tobc introduced into the pipe and taniped down -around lthe rods. When the space in the pipe has been filled, the rods are drawn out and the compound cooled, so that it becomes very hard.

The number of rods will depend on the number of wires which the pipe is designed to contain.- I prefer to string one wire in each passage formed, and the -rods should be of sufficient diameter to leave a 'passage through which the wires may be readily drawn. There should be about th rce-quarters of an inch space between the walls of one of these passages and In another application Iv have shown pipe; B, the filling of insulating material, and

the inner surface of the pipe, or between any two passages.

The inclosing-pipe may be in sections ser# eral feet in length, and the sections. may-have any -well-l nown lor convenient form'of coupling or joint.

In the d rawi ugs I have shown several forms, and- I shall now refer to the same for a more detailed'dcscription of the device. Figure 1 is a'plan view of apart of the underground systemto which, as before explained,my invention is especially applicable. Fig. 2 is a broken vertical section taken through the centers of the junction-boxes or man-holes. Figs. 3, 4, and 5 are longitudinalI and transverse'sections of pipes constructed in-accordance with" my invention, andprovided with different forms of coupling enjoint. Fig. 6 is a longitudinal section of a' form of joint` suited to pipes containing but one passage for wires.

spending parts in all the figures. Y

Referring to Figsy3 to 6, inclusive, Adeslgnates an ordinary iron or other rigid metal C the passages for the wires.

The compound which I use one composed of the ingredients above specified,in about the following proportions: Fifty gallons of coal-tar before distillation, two gallons of parafline, one hundred and fifty pounds of silicious sand, fifty pounds of ashes and cinders, two pounds of the oxide of manganese, and one of ammonium chloride. These materials are thoroughly mixed and heated.

The particular manner of making the pipe is immaterial. The simplest process of which I am aware is to 4pass a section of pipe over the desired number of rods or tubes and to fill in the space remaining in the pipe with the matcrialwhile hot and soft, tamping it down to render it solid. Then, when the pipe is filled, the tubes or rods are drawn out, leaving the passages through the insulating-filling. The latter becomes very hard when cold and adheres firmly to the pipe.

The pipe itself may be in cross section round, square, hexagonal, or of otherdesired shape, and the ends are provided with any suitable form of coupling.

fortheniiiugis' In Fig. 4 the coupling shown is a form of union couplingthat is, one section of pipe has a plain flange, d, over which is a threaded sleeve, c. rl"he end oi' the next sect-ion 1s enlarged and threaded to-connect with'the sleeve.

In Fig. 5 the ends of bothsections are threaded and joined byaai'rternallyfthrcaded coupling, These forms ot' coupling are adapted -i'or' use with pipes containing two or -mtre insulated passages. When only one ecnlines.

tral passage is used, the common form of serew-joint is suitable. Of this form Fig. Gis an illustration.

In practice I use these pipes in the systems partially illustrated. in Figs. l and 2. In these figures, I) represents the main-llne pipe or conduit for containing the circuits ol' local telephone or telegraph systems, and E a similar conduit for electric-lightor power circuits, F is a main trunk-line conduit: for telegraph- These pipes are iliade entirely of the insulating compound used in the interiorof the iron pipes above described.' are however buried at such a'deptli and are of such size that this is practicable.

For the branch pipes, or those which carry the branch circuits oil' to the houses along the Way, I use the iron pipes llled with the insulating compound. These pipes are much smaller andare near the surface, and great economy is secured by the use of the iilled iron pipes. The wires are brought up from the mains through what I termhund-holes,

The mains designated by G H. Theseare boxes or ehambers made of the same material as the mains and closed with a suitable cover. The ends of the branch pipes are simply inserted througitI walls of the boes, and in any' space that may be left some of the insulating material in a ,soft state is packed.:' I do not claim hereinthis particular arrangement of pipesfthe same being shown merely forthe pur- 'p'oseof illustrating the uses and advantages of theiron pipes filled with the insulating compound in the manner set fort-h.

'I am aware that iron and other pipes have been filled with insulating compounds for the protection ol'electric conductors; so faras I am aware, h'owever,the wires are either embedded in the material, or else theinsulating material has Abeen previously molded in blocks which are inserted inV the pipe. My invention diflcrs from th'esc in several important particulars. The wine-passages are formed in a completed pipe and the wi-re afterward introduced as needed. The pipe orconduit is solid and durable, the material used having the prop erty of adhering perfectly to the iron.

An underground conduit composed of scctions each formed ot' an iron casing or tube with couplings,and a filling of insulating compound composed ot coal-tar, paratline,silicious sand, pulverized ashes and cindcrs, oxide of manganese, and ammonium chloride, the said filling being provided with one or more passages or ducts for containing electric conductors, all as set forth. 4

DANIEL II. DORSETT. \\"it1iesses:

JAS. DANIEL COMPTON, PAR Kun. \V. Pau ic. 

